While much of Siggraph is focused on behind-the-scenes looks of the latest visual effects, animation and game projects — Disney’s “Tron Legacy” met an enthusiastic reception — the conference has a vibrant Emerging Technologies section, showcasing advanced research on robotics and human-computer interaction. Those innovations and larger shifts at the show hint at a very different future from what the makers of “Tron” imagined.

It’s no longer about humans getting inside the virtual world. The virtual world is extruding into ours.

One hot area in emerging technologies is ways to interact with computers more physically than by hands and fingers on a keyboard, mouse or screen. At one extreme that’s what motion-capture is, and real-time motion capture has been a hot topic at Siggraph for years. This year’s mo-cap demos show it getting smaller, faster, more accurate and cheaper. So far it’s still mostly for pros, but it has huge potential for gaming and entertainment — what is a Wii but a small mo-cap device for consumers? Imagine a world in which mo-cap goes entirely markerless and is much more sensitive, or where it’s not limited to a confined space. In effect, a user could be moving around in the real world and the cyber world at the same time.

Researchers are also busy inventing ways for computers to touch us just as we touch them. One presentation used a small device with small rods on one end to press on a user’s skin in response to light and shadow at the other. Think of it as a step toward being able to record, duplicate and send a touch the way we now do with a photo. The implications of that for “immersive” content are enormous, even aside from the obvious possibilities for the adult industry.

Some once-obscure technologies for merging the computer and real worlds are already moving toward the mainstream. Three-dimensional printing lets artists design an object and then fabricate it quickly in plastic, rather than simply admire it on their screens. 3D printers are already finding use in the movie industry for rapid prototyping, and the number of companies touting them is growing.

Some merging of the computer and real worlds is still new enough to be menacing. “Tron Legacy” director Joseph Kosinski told Siggraph that his pic explores the idea that the digital avatars we create through our digital lives can be separate and very different from ourselves, and not necessarily our friends.

But the look of the computer world is much more familiar than we thought it would be in 1982. If gamers could truly get inside one of today’s console games, they’d probably find something that looked more like “The Expendables” than the stylized shapes and day-glo colors of the original “Tron.”

Videogames have become much more detailed and realistic, imitating movies, while movies have become faster-paced and visually dense, imitating games. Even vidgame-to-movie adaptations like “Prince of Persia” and the “Resident Evil” franchise resemble good old-fashioned action movies more than they do “Tron.”

For showbiz pros, the recent Siggraphs have felt tiny compared to years past. (Vets of the confab get wistful reminiscing about the huge, lavish parties of the 1990s.) The tradeshow is especially shrunken. Yet it remains an essential event for recruiting and sharing knowledge, whether it’s the cutting-edge output of the Emerging Technologies section or the simple sharing of the history of the field from veterans to students.By show of hands, five or so people who worked on the original “Tron” were in the audience for Tuesday’s “Tron Legacy” panel. They got a big hand. But that’s no surprise at Siggraph, where every year the dream they spin of getting inside the computer is invented anew.